Mandarin plant named Merbeingold 2350

ABSTRACT

Merbeingold 2350 is a new Australian variety of mandarin. It was selected from the progeny obtained following a controlled pollination of Imperial mandarin×Ellendale tangor in 1984. It was selected because it is strongly parthenocarpic and is capable of yielding seedless fruits, which are sweet, juicy and easy-to-peel. Fruit maturity is mid season in the Murray Valley of Australia. The rind of Merbeingold is thin, orange-to-orange red, strong yet easily peeled. Its fruits can be snap picked, eliminating a need to clip. Internally, the flesh of Merbeingold 2350 is attractive, orange in colour and juicy with a good sugar/acid balance.

This application claims priority of Australian Plant Breeder's RightApplication No. 2006/278, filed Oct. 16, 2006, the contents of which areincorporated by reference herein.

Merbeingold 2350 was accepted for Plant Breeder's Right (“PBR”)registration on Dec. 1, 2006 when a provisional PBR was granted.Acceptance was published in the Plant Varieties Journal (2007) Vol. 19,No 4, p23 (see, ipaustralia.gov.au/pdfs/plantbreed/PVJ_(—)19_(—)4.pdf).The Commonwealth of Australia Plant Breeder's Rights Act 1994 followsthe guidelines of the International Convention for the Protection of NewVarieties of Plants—UPOV Convention (1961), as revised at Geneva (1972,1978 and 1991). Australia is a UPOV Member State.

LATIN NAME OF THE GENUS AND SPECIES OF THE PLANT CLAIMED

Citrus reticulata×(C. reticulata×C. sinensis)

VARIETY DENOMINATION

Merbeingold 2350

BACKGROUND OF THE INVENTION

Merbeingold 2350 is a new variety of mandarin (Citrus species) bred byCSIRO Plant Industry. A copending application has been made for thevariety Merbeingold 2336, which is a sibling selected from the samefamily as Merbeingold 2350.

Merbeingold 2350 is a mandarin variety selected from a family producedby making a controlled cross between Imperial mandarin (seed parent)with Ellendale tangor (pollen parent). Thus, the botanical name for theplant is:Citrus reticulata×(C. reticulata×C. sinensis)

The plant may be used for horticultural production of mandarin fruits.

Merbeingold 2350 was selected from a family of 241 hybrids generated bya controlled cross-pollination of Imperial mandarin (maternal parent)with Ellendale tangor (pollen parent).

Imperial mandarin is an Australian variety that originated at EmuPlains, NSW, as a chance seedling in 1890. It is possibly a hybrid ofthe Mediterranean mandarin. Imperial trees are vigorous, upright and ofmedium size and they yield fruits that are early maturing.

Ellendale tangor is another Australian variety that was discovered as achance seedling at Burrum, Queensland in 1878. Although its parentage isunknown, its characteristics and fruit size indicate that it is a tangor(mandarin×orange cross). Ellendale trees are generally large and of aspreading-round habit and produce large mid-to-late season fruitdepending on where they are grown.

The seediness of fruits from both Imperial and Ellendale can be variableranging from many-to-few-to-zero depending on the proximity of othersources of pollen. Both varieties are capable of producing fruitsparthenocarpically.

CSIRO crossed Imperial with Ellendale to combine the characteristics ofthe two varieties and generate new parthenocarpic hybrids for selectionof potential new varieties of seedless mandarins.

The controlled cross-pollination was conducted by emasculating anun-opened flower bud of the maternal parent and applying pollen from thepaternal parent to the receptive stigma using a sterile soft-hairedpaintbrush. Pollen of Ellendale tangor was collected by drying anthers,which had been removed from unopened flower buds, in Petri dishes oversilica gel in a dessicator. Dried dehisced anthers were stored in sealedglass vials over silica gel at 4° C. until needed. The cross was made in1984 and the resultant seeds were extracted from fruits in 1985 and sownin a standard seed bed under glasshouse conditions. Emergent seedlingswere transferred to a standard potting mix in pots and maintained underglasshouse conditions until they were rowed out in the breeding orchardat a planting density of 2 m within and 6 m between rows. Hybridseedlings were maintained under irrigated orchard conditions thereafter.Standard citrus cultivation techniques were used to maintain the treesincluding application of fertilisers.

When hybrid 2350 flowered, it was subjected to a range of pollinationtreatments to assess its potential for producing seedless fruits. Fruitswere harvested over 4 years and assessed for fruit quality, Based on thedata collected, hybrid 2350 was selected for entry into second phaseevaluation trials. The selection was entered into a comparative trial atCSIRO Plant Industry Koorlong (NW Victoria). It was also entered alongwith other selections into regional test plots with anonymouscooperating citrus growers under confidential testing agreementarrangements to protect inherent intellectual property. Based on itsperformance in these trials and test plots, hybrid 2350 was namedMerbeingold 2350.

Daughter trees of Merbeingold 2350 propagated from the original seedlingtree by asexual or vegetative means are uniform and stable. Similarlygrand-daughter trees are uniform and stable. Trees of Merbeingold 2350have been propagated by grafting or budding to seedling rootstocks, bytop-working to established orchard trees and by rooting cuttings,confirming its uniformity and stability.

SUMMARY OF THE INVENTION

Fruits of Merbeingold 2350 have the capacity to be seedless and seednumbers are dependent on cross-pollination. In regional test plots, meanseed numbers have ranged from less than 1 up to 10 seeds per fruit. Lowseed numbers have occurred where trees are planted close to naveloranges, which because they are pollen sterile, cannot cross-pollinateMerbeingold 2350's flowers. Under these circumstances, seedless andlow-seeded fruits have been harvested. Where higher seed numbers havebeen recorded, trees of Merbeingold 2350 have been surrounded by strongpollen producers such as Valencia orange, Murcott tangor and Minneolatangelo. In these situations, cross-pollination is promoted and seedierfruits result. Clearly, successful adoption of Merbeingold 2350 toproduce seedless and low-seeded fruits will depend on its location withregard to potential cross-pollinator varieties. In orchards where seednumbers have been one-or-less per fruit, a large proportion of thefruits have been seedless.

The rind is thin and the fruits are easy-to-peel leaving segments freeof albedo tissue. The segments are readily separated without breakingand are tender with soft walls resulting in a pleasant texture wheneaten. The rind, though thin, is strong giving a robust intact fruitsuggesting it will ship well and be suited for export.

The juice is sweet with a °Brix of around 11-12. With an acidconcentration of 1% or just under at maturity, fruits of Merbeingold2350 have a pleasant sweet flavour. The juice does not have an overlydistinctive flavour.

The rind is an attractive red-orange which should have high appeal inthe market place. In this regard, the fruit has been compared to thevariety Nova but it does not appear to suffer granulation like Nova.Fruits of Merbeingold 2350 can be snapped from the tree leaving thebutton intact. They reach maturity during the period lateJune-through-August in Australia's Murray Valley depending on soil type,rootstock and season. Fruit size is good with mean fruit weights in therange 120-140g.

BRIEF DESCRIPTION OF THE DRAWING

FIGS. 1A-1C: Show leaves from Merbeingold 2350 (FIG. 1A) and itsparents, Imperial mandarin (FIG. 1B) and Ellendale tangor (FIG. 1C). InMerbeingold 2350 the Lamina length:width ratio=2.2±0.2; in Imperialmandarin the Lamina length:width ratio=2.7±0.2; and in Ellendale tangorthe Lamina length:width ratio=2.1±0.2

FIGS. 2A-2C: Show fruit of Merbeingold 2350 (FIG. 2A) and its parents,Imperial mandarin (FIG. 2B) and Ellendale tangor (FIG. 2C).

DETAILED BOTANICAL DESCRIPTION OF THE PLANT

Variety—Merbeingold 2350

Citrus reticulate×(C. reticulata×C. sinensis)

Descriptors used herein from 1) European Union Community Plant VarietyOffice, Protocol for distinctness, uniformity and stability tests.Citrus L.—Group 1 MANDARINS. CPVO-TP\201\1 Adopted Nov. 11, 2004, and 2)IPGRI (1999) Descriptors for Citrus. International Plant GeneticResources Institute, Rome, Italy (ISBN 92-9043-425-2).

-   Plant: Diploid, growth habit spreading-to-upright, tree shape    spheroid-ellipsoid, density of branches medium, branch angle narrow,    trunk surface smooth, shoot tip green and surface glabrous.-   Spine (thorn): Either absent or very sparse on adult tree, length on    adult tree short <5 mm, shape straight.-   Leaf: Evergreen, type simple, shape ovate, intensity of green colour    on lamina medium-to-dark, colour variegation absent, margin very    weakly dentate-to-mostly entire, shape of apex acute, lamina length    medium (85±8 mm), lamina width narrow-to-medium (39±3 mm), lamina    length to width ratio 2.2±0.2, cross-sectional shape intermediate,    lamina undulation absent-to-very slight, lamina attachment    brevipetiolate, petiole length short (10±3 mm), petiole wings    obdeltate and very narrow, petiole attachment to stem curved,    junction between petiole and lamina articulate, colour of lamina    upper/lower surface same.-   Flower: Hermaphrodite, arrangement solitary and as a raceme,    position axillary and terminal, length of petal short-to-medium,    anther colour medium yellow, viable pollen sparse-to-normal, length    of anther relative to style shorter (inferior), colour of open    flower white, 5 petals per flower, stamens >4 per petal, style    straight and complete, self-compatible.-   Fruit: Maturity mid-season (late June-August, Australia), borne both    inside and outside canopy, obloid, attachment to stalk    medium-to-strong, broadest at equator, shape in transverse section    circular, base flattened-to-slightly concave, apex flat-to-truncate,    neck absent, slight depression at stalk end, number of radial    grooves at stalk end intermediate, collar absent, distal part    flattened, no depression at distal end, areola absent, stylar end    closed, stylar scar small, style not persistent, navel opening    absent, radial grooves at distal end absent, rind surface    predominantly orange-to-orange red, surface glossiness strong,    surface roughness medium, rind smooth to slightly pitted, oil glands    all more-or-less same size, pitting of oil glands present pebbling    absent, oil glands conspicuous, small and of low density, rind thin    (2-3 mm), rind adherence to flesh weak-to-medium, rind strength    strong, rind oiliness medium, albedo white and loose, amount of    albedo adhering to flesh very small, albedo strands absent, flesh    medium-to-dark orange, pulp colour uniform, pulp firmness    intermediate, pulp texture fleshy, core small-to-medium, round and    sparsely filled, segments uniform, rudimentary segments absent,    number of well developed segments medium (5-to-10; mean 9.1±0.7),    adherence of segment walls to each other medium, strength of segment    walls medium, vesicle length long, vesicle thickness medium-to-thin,    navel absent, juiciness high, soluble solids medium-to-high 9-15    °Brix, acidity medium, strength of fibre medium, parthenocarpy    present.-   Seed: Number of seeds under controlled manual self pollination few    (0-4), 0-to-15 under open pollination depending, on proximity of    other pollen sources, monoembryonic, shape ovoid, length short,    width narrow, surface smooth, external colour whitish/cream, colour    of inner seed coat light brown, chalazal cream, cotyledons    white-to-light yellow-cream.

1. A new and distinct parthenocarpic mandarin variety named Merbeingold2350 as illustrated and described.